Fuel consumption typically improves after break in is complete/1st oil change.
Also, the sticker on the Scrambler tank says 'minimum RON95 fuel' (because it's a European bike). Using a lower RON fuel will decrease mileage slightly.
Fill her up with at least a RON 91 with additives, like Shell V Power etc.
The other culprits could be - a 'rev happy riding style', low tire pressures, low engine oil, a dry chain, brake pads etc.
It wouldn't harm to bring up this issue at your first service and get everything checked properly. 33mpg sounds like an unusually low number.
edit: just realised there is already an entire thread on this topic:
http://www.ducatiscramblerforum.com/forum/ducati-scrambler-general-discussion/10058-mpg-us.html